Sexual disorders have been frequently reported in chronic alcoholic men but effective treatment and preventive measures have been limited by the paucity of empirical information on the nature, prevalence and pathogenesis of their sexual difficulties. This proposal is to assess within a cross- sectional and controlled framework the organic, psychological and relationship parameters and to investigate the interactive effect of these variables in the sexual functioning of a well-defined population of alcoholic men. Specifically, the central aims of the research are: (1) to describe the sexual functioning of a sample of abstinent chronic alcoholic men living with a female partner for at lease one year, (2) to evaluate sleep parameters and degree of erectile capacity by means of nocturnal penile tumescent (NPT) recordings and to investigate the relation between NPT and sexual functioning, (3) to assess pituitary gonadal hormones during sleep and to explore the relation between the endocrine variables and sexual functioning, (4) to assess systematically psychological and marital factors in relation to sexual functioning, and (5) to explore the interaction between psychological, relationship dimensions and physiological measures on the extent of sexual dysfunction. A sample of 105 chronic alcoholic men who are abstinent and free from coexisting medical illnesses or medications, between the ages of 25 to 60, will be selected for study. They will be compared to 40 healthy non-alcoholic controls who are free from sexual dysfunctions and who meet similar inclusion/exclusion criteria. During the initial phase several sessions will be devoted to screening each couple, assessing the alcoholic history, psychosexual behavior and psychopathology, conducting a medical evaluation and blood chemistries and administering a battery of psychological instruments. In the second phase, subjects will be scheduled for four nights in the sleep laboratory for the recording of EEG, NPT and the sequential determination of testosterone, bound and free, LH, prolactin and estrogen during sleep. The relation between biomedical and psychological variables and sexual functioning will be explored by analysis of variance, analysis of covariance, correlation analysis and multiple regression techniques. Conceptually, this study will be based on a multi-disciplinary framework which will incorporate valid psychological measures and objective biomedical procedures and techniques. It will generate information of value for predictive studies as well as for the development of effective diagnostic and therapeutic approaches for sexually dysfunctional alcoholic patients.